Collaborative research: Controls of climate and dust on soil chemical erosion and nutrient supply

合作研究：气候和灰尘对土壤化学侵蚀和养分供应的控制

• 批准号: 1946856
• 负责人: Sarah Aarons
• 金额: $ 32.2万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-02-15 至 2023-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1946856&HistoricalAwards=false
• 关键词: Collaborative; research; Controls; climate; dust

Soils are a critical component of Earth’s surface environment. They are storehouses of nutrients that sustain life, they provide habitats for plants and animals, and they influence Earth’s climate through their role in the global carbon cycle. This project’s main goal is to quantify how climate and dust affect soil chemical erosion rates and soil’s nutrient content. This is of interest because chemical erosion accelerates landscape evolution and modulates Earth’s climate, and because dust is a key source of nutrients to soils. To investigate these linked phenomena, this project will establish a series of study sites along two altitudinal transects at San Jacinto Peak, California, where nearly 3 km of relief creates a striking climate gradient with a range in mean annual temperature of 18 degrees C. This work will support a team of two early career faculty (one female, both pre-tenure), and will promote diversity initiatives through the support of the PI team, one whom is a member of an underrepresented group (Alaska Native), as well as through the recruitment of students via on-campus programs for students from underrepresented groups. Outreach and education activities will focus on developing resources for middle school teachers in collaboration with experts at the San Diego County Office of Education and the University of Wisconsin Geology Museum.Despite longstanding expectations that climate should strongly affect chemical erosion rate, quantifying these effects in nature has proven difficult, partly because these rates are difficult to measure, and partly because other factors like lithology and dust can obscure climatic effects. Dust’s impact on soil nutrient supply is likewise an ongoing topic of contention, partly because it depends on rates of soil production and chemical erosion, which are rarely measured in the same places that dust deposition rates are. The proposed work will avoid these issues by combining measurements of chemical erosion rates, climate, and dust deposition rates and provenance at SJP, which spans the largest range in temperature within a single unglaciated lithology in the United States. This will build on previous work by applying novel radiogenic isotope measurements in bedrock, soil, dust and vegetation. These data will quantify the sensitivity of chemical erosion rates to climate and provide new insights into spatial and temporal variations in dust’s impact on soil nutrient supply, which is not well constrained at the seasonal time scales that will be targeted in this work. More broadly, this work has the potential to remove a barrier to understanding how Earth’s topography, surface chemistry, and the dust cycle evolve under spatially variable climates—a common feature of Earth’s mountain ranges. Ultimately, these measurements across one of the most striking climate gradients in the United States should guide future efforts to include climate and dust explicitly in models of the topographic and chemical evolution of the Earth’s surface.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

土壤是地球表面环境的关键组成部分。它们是维持生命的营养物质的仓库，它们为动植物提供栖息地，并且通过在全球碳循环中的作用来影响地球的气候。该项目的主要目标是量化气候和尘埃如何影响土壤化学侵蚀率和土壤的营养含量。这很有趣，因为化学侵蚀会加速景观的进化并调节地球的气候，并且因为灰尘是土壤营养的关键来源。 To investigate these linked phenomena, this project will establish a series of study sites along two altitudinal transects at San Jacinto Peak, California, where almost 3 km of relief creates a striking climate gradient with a range in mean annual temperature of 18 degrees C. This work will support a team of two early career faculty (one female, both pre-tenure), and will promote diversity initiatives through the support of the PI team, one whom is a member of an代表性不足的小组（阿拉斯加本地人）以及通过校园课程招募学生的计划，该计划为来自代表性不足的小组的学生提供。外展和教育活动将专注于与圣地亚哥县教育办公室和威斯康星大学地质博物馆的专家合作开发资源。灰尘对土壤养分供应的影响同样是一个持续的争论话题，部分原因是它取决于土壤的产量和化学侵蚀的速率，这些损失率很少在灰尘沉积速率的相同位置进行测量。拟议的工作将通过结合化学侵蚀速率，气候和灰尘沉积速率的测量以及在SJP的证明来避免这些问题，该速度涵盖了美国单个无酸化岩性的温度范围最大。这将基于以前的工作，通过在基岩，土壤，灰尘和植被中应用新颖的放射性同位素测量。这些数据将量化化学侵蚀速率对气候的敏感性，并为灰尘对土壤养分供应的影响的空间和临时变化提供新的见解，这在这项工作中将在季节性时间尺度上受到很好的约束。更广泛地说，这项工作具有消除障碍的潜力，可以理解地球的地形，表面化学和在空间可变的气候下如何发展，这是地球山脉的共同特征。最终，在美国最引人注目的气候梯度之一中的这些测量值应指导未来的努力，以明确的努力在地球表面的地形和化学演变模型中明确包括气候和灰尘。该奖项反映了NSF的法定任务，并通过使用该基金会的知识分子的智力和更广泛的影响来评估NSF的法定任务，并被视为珍贵的支持。